1. Field of the Invention
The present invention relates to a side-light type liquid crystal display device.
2. Description of the Related Art
A liquid crystal display device includes a liquid crystal module including a liquid crystal panel and a backlight unit. FIG. 4 is a schematic exploded perspective view of a conventional liquid crystal module 2 including a side-light type backlight unit. A liquid crystal panel 4 serving as a display panel is arranged on a front side of the liquid crystal module 2, and a backlight unit 6 is arranged behind the liquid crystal panel 4. The backlight unit 6 has a laminated structure in which a lower frame fitting 8, a reflective sheet (not shown), a light guide plate 12, an optical sheet 14, and the like are laminated in order from a rear side of the backlight unit 6. A light source 16 is arranged at a lateral surface of the light guide plate 12. The laminated members other than the lower frame fitting 8 are thin plates made of a synthetic resin and the like, and are relatively flexible. The lower frame fitting 8 functions as a support member for supporting a rear side of the laminated members other than the lower frame fitting 8. Further, the lower frame fitting 8 includes a light guide plate support pin 18 which is a protrusion provided upright, for supporting the light guide plate 12. The light guide plate support pin 18 is provided at a position at which an edge of the light guide plate 12 is to be situated. On the other hand, the light guide plate 12 includes, at the above-mentioned position, a cutout portion (engaging concave portion) 20 to which the pin 18 is fitted. Under a state in which the backlight unit 6 is assembled, the light guide plate support pin 18 is inserted through the cutout portion 20, thereby preventing the light guide plate 12 from shifting.
FIG. 5 is a partial plan view schematically illustrating the light guide plate 12, the cutout portion 20, and the light source 16. The light source 16 is arranged so as to cause light to enter an effective display region 22. The cutout portion 20 is provided outside the effective display region 22.
Note that, a protruding portion was formerly provided at an edge of the light guide plate, and the light guide plate was fixed by causing the protruding portion to be caught in a concave portion provided to a mold frame or the like, which surrounded the periphery of the light guide plate. However, in view of attaining a narrower frame, a structure in which the protruding portion is provided to the edge of the light guide plate has a disadvantage. In contrast, a structure in which, as illustrated in FIG. 5, the cutout portion 20 is provided so as to cut inside a side 24 of the light guide plate 12 having a substantially rectangular planar shape has an advantage for attaining a narrower frame.